public class Test {
    //山脉数组的顶峰(即使用log级别的时间复杂度找到数组中的最大值的下标)
    public int peakIndexInMountainArray(int[] arr) {
        int left=0,right=arr.length-1;
        while(left<right){
            int mid=left+(right-left+1)/2;
            if(arr[mid]>=arr[mid+1]){
                left=mid;
            }else {
                right=mid-1;
            }
        }
        return left;
    }

    public int findPeakElement(int[] nums) {
        //寻找多个峰值
        int left=0,right=nums.length-1;
        while(left<right){
            int mid=left+(right-left)/2;
            if(nums[mid]<nums[mid+1])left=mid+1;
            else right=mid;
        }
        return left;
    }


}
